Propeller assisted steering and automatic torque compensation for an outboard motor



J y 1951 w. c. coNovER 2,993,464

PROPELLER ASSISTED STEERING AND AUTOMATIC TORQUE COMPENSATION FOR ANOUTBOARD MOTOR Filed Aug. 5, 1957 2 Sheets-Sheet 1 INVENTOR. l/IAKZ'A/C; [an 0V5? A rra/erltv July 25, 1961 w. c. coNovER 2,993,464

PROPELLER ASSISTED STEERING AND AUTOMATIC TORQUE COMPENSATION FOR ANOUTBOARD MOTOR Filed Aug. 5, 1957 2 Sheets-Sheet 2 I N V EN TOR. Wine?61 Can/0Y5? will, m w

United States Patent 2,993,464 PROPELLER ASSISTED STEERING AND AUTO-MATIC TORQUE COMPENSATION FOR AN OUT- BOARD MOTOR Warren C. Conover,Waukegan, 111., assignor to Outboard Marine Corporation, Wankegan, 111.,a corporation of Delaware Filed Aug. 5, 1957, Ser. No. 676,125 14Claims. (Cl. '115-18) is ofi center regarding its own axis in order toinsure that the resultant center of pressure of forces acting on the tabwill trail the axis. If its greatest area is aft of the axis, it will besubject at all times to bias tending to restore it to center and will bemore stable in operation. In steering, either by means of a tillerhandle or from a remote wheel, the connections are such that steeringmovement is first effective on the miniature rudder or trim tab to turnthis in a direction to exercise its steering effect to oscillate thedirigible parts of the outboard motor in the desired direction. Boatdirection is changed only by oscillation of the dirigible unit.

After the trim tab reaches its limit of movement, further action of thetiller or steering cable is transmitted mechanically to the dirigiblepropulsion unit of the outboard motor to turn this, aided by the rudder,in the desired direction upon its steering axis. Ordinarily, except whenthe outboard motor enginehas stopped, or is in very slow speedoperation, the displacement of the miniature rudder is sufl'icient initself to effect steering oscillation of the outboard motor to thedesired steering angle, using the thrust of the propeller slip stream toeffect steering movement. With the engine in slow speed operation, theslip stream may be inadequate to effect steering movement, but thethrust exerted by the control rudder will aid steering.

Thus, the steering is either power effected or power assisted under allconditions by the propeller of the outboard motor when in operation.With the propeller at rest or in reverse, the control rudder will havelittle or no effect. Assuming that the control rudder is behind thesteering axis, its direction of rotation will be opposite to thedirection of rotation of the dirigible unit, but forces caused by itsdeflection in the opposite direction are too small to interfere with thesteering effect of the rudder shaped gear housing of the dirigible unititself.

In the drawings:

FIG. 1 is a front quarter perspective view of an outboard motorembodying the invention, portions being broken away to expose thesteerng mechanism.

FIG. 2 is a fragmentary view on an enlarged scale showing the outboardmotor in side elevation, the power head being removed and portions beingbroken away to a vertical fore and aft section.

FIG. 3 is a diagrammatic plan View showing the outboard motor applied toa boat, the power head being removed.

FIG. 4 is a fragmentary view in perspective showing an arrangementwhereby the control rudder is actuated by a tiller mechanically linkedthereto for the operation of the control rudder and, ultimately, theoscillation of the dirigible portions of the outboard motor-a FIG. 5 isa view in side elevation of the dirigible propulsion unit portion of anoutboard motor, portions being broken away and the power head beingomitted.

FIG. 6 is a plan view of the parts shown in FIG. 4.

FIG. 7 is a view similar to FIG. 6 showing how the same device can beremotely controlled by connecting cables to the tiller.

Except for the power assisted steering herein described, the outboardmotor may be of any conventional design. The power head 5, shaft housing6 and lower unit or gear housing 7 are unitarily connected and mountedon pintle 8 from transom bracket 9 to oscillate for steering. Thestreamlined gear housing or lower unit 7 acts as a rudder, but thesteering of the boat 10 on which the transom bracket is mounted isprimarily effected by directing to one side or the other the slip streamof propeller 11. a

When such an outboard motor is to be steered from some remote point, asfrom the bow of the boat 10, one conventional practice is to provide atthe remote point a steering wheel 12 having a drum 13 upon which thesteering cable 14 is wound. The pulleys 15, 16, 17 and 18 fixed to theboat guide the steering cable and its ends are normally connected to thediribible portions of the outboard motor well forward of the steeringpintle 8 whereby the rotation of the steering wheel 12 will oscillatethe outboard motor steering unit in either direction, according to thedirection of rotation of the steering wheel. Rotation of the steeringwheel clockwise as viewed by the operator looking forward will wind ontothe drum 13 that portion of the cable which passes about pulleys 15 and16 to oscillate the dirigible unit of the outboard motorcounterclockwise as viewed in FIG. 3. In the course of this steeringmovement, the length of cable passing about pulleys 17 and '18 will bepayed oif of the drum 13 to accommodate the counterclockwise swingingmovement of the dirigible unit. A converse movement of the steeringwheel 12 in a counterclockwise direction as viewed by the operator willwind onto the drum the cable passing about pulleys 17 and 18 and and payout cable passing about pulleys 15 and 16 to effect clockwiseoscillation of the outboard motor dirigible unit as viewed in FIG. 3.

However, instead of being connected rigidly to the forward portions ofthe dirigible unit, the two lengths of cable pass about the pulleys 19and 20 which are mounted on carrying handle 21 or some other part of themotor well forward of pintle 8 which is firmly attached to the dirigibleunit. The end of cable length 40 is attached to a tiller 22 at the portside of the control rudder post 23 on which control rudder 25 ismounted. The shaft housing 6 is provided with an arm at 27 whichprojects aft to provide a bearing support for the rudder post 23. Alower bearing support for the rudder post 23 is provided in the aft endof the anticavitation plate 28 as best shown in FIG. '1 and FIG. 2.

A portion 29 of the cable is led from the pulley 20 to connect to thestarboard end of the tiller 22. Stops 30 and 31 are positioned in thepath of oscillation of the tiller lever 22 to iimit it to a range ofapproximately 30 in either direction of oscillation from its normalposition longitudinal of the boat.

While it is broadly immaterial whether or not the rudder 25 is locatedbehind the dirigible portions of the outboard motor, it is preferredthat it be located directly in the slip stream of the engine drivenpropeller 11 of the outboard motor. It is small enough so that it willhave no appreciable steering elfect except as acted upon by the powerfulslip stream from the propeller. Consequently, it has no substantialeifect on the steering of the boat as a whole but, with the propeller innormal powered operation, the slip stream exerts on the control causingthe control rudder to center itself. feathering effect is a verydesirable feature of the device.

tiller 22 at the rear of the dirigible unit but passes about pulleys 19and 20 which are mounted on the front of'the -unit. Thus, as-the unitturns, the cable which was wound up ,is relaxed and that which waspayed-out is tensioned,

This self- It occurs inevery position to which the steering wheel isadjusted.

Moreover, if the steering wheel or cables (if these are employed) areheld fixed, the rudder will automatically adjust itself to oppose anyexternally caused displacement of the lower unit or dirigible part ofthe outboard motor. To the extent towhich there'is any thrust whateverexerted by the slip stream on the control rudder 25,

such thrustopposes the displacement of the control rudder from itsnormally centered position and the reaction of this'thrust requires thecable to exert steering tension on one or the other of the pulleys 19 or20 to oscillate the dirigible unit of the outboard motor in the desiredsteering direction. The operator in turn must continue to exertsufiicient force on wheel 12 to keepcontrol rudder 25 turned until hewishes to stop the dirigible unit from further movement. Accordingly, inall instances of normal use with the propeller in operation, the effect"is one of power assisted steering rather than entirely automaticsteering'and the dirigible unit will'respond accurately in direction andextent of movement to the movement of the wheel 12;

. Ifthere is no substantial propeller thrust, there will, obviously, be'little or no reaction forces as above'described but, after the controlrudder has yielded to the limited extent permitted by the stops 30 and31, the steering cable will, in effect, be locked between drum 13 andthe forward portion of the dirigible unit of the outboard motor to whichhis connected-by passing about the now stationary pulley'19 'o'r 20;Accordingly, after a limited amount of lost motion resultin'gfrom thefree movement of the tiller, the steering'wil-l :take place exactly asitwould without'the control rudder.

The embodiment shown inFIGS. 4 to 7 achieves these objectives in aslightly different manner. Here the rud- 'der 250 is mounted on rudderpost 23' slightly above the propeller 11. The llever220 on the top ofthe steering post oscillates between the stop [lugs 300 and 310 whichlimit its range of oscillation to the angle which is appropriate for theindependent oscillation of the rudder. The link 41 connects rudder postlever 220 with one end of a lever 42, the other end of which isconnected by link 43 with a bell crank 44 extending laterallyfrom amanually operable tiller 45. The'tiller has a hand grip at '46 in tendedto be grasped by the operator during operation. However, for remotecontrol purposes, the'hand gn'p may be removed and linkages, push-pullcable, or the illustrated lengths of solid steering cable 29 and 40 maybe connected directly to the tiller 45 as shown in 'FIG.7.

The operation of the device shown infFIGS. 4 to '7 is identical withthat already described. In any steering movement'of the tiller, whethereffected through manual engagement of grip 46 or remotely through thecables 29 and 40, it is first communicated to the trim tab or rudder250. 'If the parts are" in rapid motion through the water, this may beadequate in and of itself to cause the dirigible portion of the outboardmotor to adjust its positionin the desired direction of steering, theadjustment stopping when the water pressure on the trim tab or rudder isbalanced. If, for any reason, .the trim tab action does not of itselfefliectthe desired steeringmovement of the dirigible ,parts oftheoutboard motor, :the engagement of lever 220 with one or the other ofthe stops 300 or 310 will arrest further independent movement of thetiller and linkage whereby continued steering movement will becommunicated directly to the dirigible parts to effect manualpositioning thereof, aided by the trim tab or rudder if the outboardmotor is in motion.

Due to the illustration of the trim tab or rudder in its preferredposition behind the steering axis, it will be ap- 'pliedto pivot in adirection opposite the direction of oscillaton desired for steeringpurposes. It is only on this account that the intermediate lever 42 isrequired to reverse the direction of oscillation of the rudder post ascompared with the desired direction of steering oscillation.

I claim:

1. An outboard motor comprising a dirigible unit having a powerhead, ashaft housing and a gear casing in rigid unitary connection andincluding a drive shaft in the housing, a propeller shaft in the gearcasing and a propeller mounted upon said shaft, means pivotallysupporting said unit for steering movement, and means for effecting theoscillation of said unit by pressure of the water in which it isoperated, said means comprising a control rudder pivotally connectedwith said unit and provided with means for its oscillation, the eflfectof the control rudder being to tend to oscillate said dirigible unit ina desired direction for steering.

2. The device of claim 1 in which said control rudder is mounted at therear of said unit and connected to oscillate in a direction opposite tothe desired steering oscillation of said dirigible unit.

3. A marine drive having a steering assisting means and comprising incombination a dirigible unit provided wth a power-operated propeller,means pivoting such unit 'for oscillation about a vertical axis forsteering, means for effecting the, oscillation of said unit by pressureof the water in which it is operated, said means comprising a controlrudder pivotally connected with said unit and provided with means forits oscillation, a tiller pivotally connected with the dirigible unitand having a lost motion connection with such unit for the steeringthereof, the tiller being pivotally movable independently of thedirigible unit in a range of oscillation provided by the lost motionconnection aforesaid, and a motion transmitting connection from thetiller to the rudder for the tiller-operated actuation of the rudder insuch range, and means defining the of such range and constituting meansfor limiting the oscillation of the control rudder, the control rudderbeing mounted behind said unit and the connection of the tillertherewith including means for effecting control rudder oscillation in adirection opposite to the direction of oscillation of the tiller uponits pivotal connection with the dirigible unit.

4. The device of claim 3 in which said tiller is provided withconnections for its oscillation from a remote point.

5. An outboard motor comprising a fixed unit, a dirigible unit having apowerhead, a shaft housing and gear casing in unitary connection,bearing means between the fixed unit and the dirigible unit in whichsaid dirigible unit is oscil latable, the torque to which said unit issubject about the axis of its oscillation being substantially in balanceby reason of the unitary connection of the power head shaft housing andgear casing, a propeller mounted on the gear casing and normallydirected aft, a rudder post in a generally upright position behindthepropeller, a control rudder mounted on the post at the rear of thepropeller in the path of the slip stream therefrom and adapted to effectdirigible movement of the'said dirigible unit, and supporting meansrespectively connected with the shaft housing and-gear casing andprovided bearings in which the rudder post is oscillatable, and means.for oscillatingthe rudder in a direction'opposite that in whichsteering movement of said dirigible unit is desired.

mitting connection with the rudder post, and means limiting the rudderpost to a limited oscillation.

7. An outboard motor comprising a fixed unit, a dirigible unit having ashaft housing and gear casing in unitary connection, bearing meansbetween the fixed unit and the dirigible unit in which said dirigibleunit is oscillatable, a propeller mounted on the gear casing andnormally directed aft, a rudder post in a generally upright positionbehind the propeller, a control rudder mounted on the post at the rearof the propeller in the path of the slip stream therefrom and adapted toefiect dirigible movement of the said dirigible unit, and supportingmeans respectively connected with the shaft housing and gear casing andproviding bearings in which the rudder post is oscillatable, and meansfor oscillating the rudder in a direction opposite that in whichsteering movement of said dirigible unit is desired, means foroscillating the rudder comprising a tiller lever in pivotal connectionwith said dirigible unit and having a motion transmitting connectionwith the rudder post, and means limiting the rudder post to a limitedoscillation, the pivotal connection of the tiller with said dirigibleunit being disposed forwardly of the axis on which the unit isoscillata-ble in said bearing means and the connection from the tillerto the rudder post including linkage having means for reversing thedirection of motion transmission, whereby the direction of oscillationof the rudder post is opposite the direction of oscillation of thetiller lever, the rudder comprising means for the dirigible movement ofsaid unit in the direction in which the tiller lever oscillates.

8. A marine drive having a steering assisting means comprising incombination a dirigible unit provided with a power-operated propeller,means pivoting such unit for steering movement, and a control rudderpivotally connected with said unit and provided with means for itsoscillation, the effect of the control rudder being to tend to oscillatesaid dirigible unit in a desired direction for steering, said dirigibleunit comprising a power head, a gear housing on which the power-operatedpropeller is mounted, and means rigidly connecting the power head andgear housing to turn as a unit upon the means pivoting said unit forsteering.

9. A marine drive having rudder assisted steering and comprising incombination a fixed unit, a dirigible unit provided with apower-operated propeller, means mounting said dirigible unit on saidfixed unit for steering movement, means for the steering oscillation ofsaid dirigible unit and comprising a control rudder in pivotalconnection with said dirigible unit, steering means connected to saidrudder to oscillate said rudder with respect to said dirigible unit in adirection to cause said dirigible unit to oscillate with respect to saidfixed unit, the connection of said steering means with said rudderincluding lost motion connection between the steering means and thedirigible unit to oscillate said dirigible unit with respect to thefixed unit in the same sense that the rudder tends to oscillate thedirigible unit with respect to the fixed unit, means limiting thesteering oscillation of said rudder with respect to said dirigible unit,the rudder being adapted to effect movement of said unit to a positionin which the rudder is in balance with respect to pressure exertedthereon by the water in which it is immersed, and tending to respondautomatically in response to any unbalance of pressure in a direction tooscillate said unit toward a position in which said balance is restored.

10. The device of claim 9 in which said rudder is located aft of saiddirigible unit and said steering means is located forwardly of thesteering axis of said dirigible unit, the steering means having motiontransmitting mechanism connecting it with said rudder for oscillatingsaid rudder in a direction opposite to the direction of steeringoscillation required of said unit.

11. A marine drive having a steering assisting means comprising incombination a dirigible unit provided with a power operated propeller,means pivoting such unit for steering movement, a control rudderpivotally connected with said unit and provided with means for itsoscillation, the effect of the control rudder being to tend to oscillatesaid dirigible unit in a desired direction for steering, said controlrudder being operatively mounted at the rear of the dirigible unit andin proximity to the propeller to be subject to propeller slip stream,means for limiting the oscillation of the control rudder, and steeringmeans connected with the control rudder, said steering means having asecondary connection efiective upon the dirigible unit when the controlrudder reaches the limit of its oscillation whereby said dirigible unitwill be moved in the same direction as normally urged by said rudder.

12. A marine drive having a steering assisting means comprising incombination a dirigible unit provided with a power operated propeller,means pivoting such unit for steering movement, a control rudderpivotally connected with said unit and provided with means for itsoscillation, the effect of the control rudder being to tend to oscillatesaid dirigible unit in a desired direction for steering, a tillerpivotally connected with the dirigible unit and having a primaryconnection with said control rudder, and means for limiting theoscillation of the control rudder whereby said tiller is efiective tobring about the oscillation of said dirigible unit when the controlrudder reaches the limit of its movement, such oscillation of saiddirigible unit being in the same direction as normally urged by saidrudder.

13. The device of claim 12 in which the rudder has a rock shaft providedwith a grooved tiller segment and the means for rudder oscillationcomprises tiller cables crossing adjacent said segment and trained aboutthe grooves thereof and connected to opposite sides of the segment.

14. The device of claim 12 in which the control rudder is provided witha rock shaft and is disposed at the rear of the propeller in the slipstream thereof, said tiller com-' prising a lever on the rock shaft, themeans for oscillation comprising tiller ropes trained from oppositedirections and connected with said lever at opposite sides of the rockshaft, the rudder being positioned by the tiller ropes.

References Cited in the file of this patent UNITED STATES PATENTS1,166,749 Dougherty Jan. 4, 1916 1,302,956 Owen May 6, 1919 1,540,079Luchsinger June 2, 1925 FOREIGN PATENTS 437,447 Great Britain Oct. 28,1935 793,426 France Nov. 23, 1935

